How many moles of sulfur dioxide (SO2) are present in 1.52 grams of this compound?
The correct answer and explanation is:
To determine the number of moles of sulfur dioxide (SO₂) in 1.52 grams of the compound, start by calculating its molar mass.
Sulfur dioxide (SO₂) is composed of:
- 1 sulfur atom = 32.07 grams/mole
- 2 oxygen atoms = 2 × 16.00 = 32.00 grams/mole
Adding these gives the molar mass of SO₂:
32.07 + 32.00 = 64.07 grams/mole
Now use the formula for moles: Moles=MassMolar Mass=1.52 grams64.07 grams/mole≈0.0237 moles\text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}} = \frac{1.52 \text{ grams}}{64.07 \text{ grams/mole}} \approx 0.0237 \text{ moles}
Correct Answer: 0.0237 moles of sulfur dioxide
Explanation:
A mole is a standard scientific unit for measuring the amount of a substance. One mole of any substance contains Avogadro’s number of particles, approximately 6.022×10236.022 \times 10^{23}. To convert a given mass of a substance into moles, divide the mass by the molar mass of the compound. Molar mass is the total mass of all atoms in one mole of a compound.
Sulfur dioxide consists of one sulfur atom and two oxygen atoms. The atomic masses used for sulfur and oxygen are based on the periodic table values. Summing them gives the compound’s molar mass.
Once the molar mass is known, dividing the given mass (1.52 grams) by this value gives the number of moles. The result, 0.0237 moles, tells how many moles of SO₂ are present in the sample. This conversion is useful in chemical reactions and stoichiometry where quantities must be compared in terms of moles rather than grams to ensure balanced chemical equations and accurate reaction predictions.